Electronic Devices with Angular Location Detection Capabilities

ABSTRACT

An electronic device may include wireless circuitry having a set of two or more antennas coupled to voltage standing wave ratio (VSWR) sensors. The VSWR sensors may gather VSWR measurements from radio-frequency signals transmitted using the set of antennas. The antennas may be disposed on one or more substrates and/or may be formed from conductive portions of a housing. Control circuitry may process the VSWR measurements to identify the ranges between each of the antennas in the set of antennas and an external object. The control circuitry may process the ranges to identify an angular location of the external object with respect to the device. The control circuitry may adjust subsequent communications based, adjust the direction of a signal beam produced by a phased antenna array, identify a user input, or perform any other desired operations based on the angular location.

This application is a continuation of U.S. patent application Ser. No.17/331,504, filed May 26, 2021, which is hereby incorporated byreference herein in its entirety.

FIELD

This disclosure relates generally to electronic devices and, moreparticularly, to electronic devices with wireless circuitry.

BACKGROUND

Electronic devices are often provided with wireless capabilities. Anelectronic device with wireless capabilities has wireless circuitry thatincludes one or more antennas. The wireless circuitry is sometimes usedto perform spatial ranging operations in which radio-frequency signalsare used to estimate a distance between the electronic device andexternal objects.

It can be challenging to provide wireless circuitry that accuratelyestimates this distance. For example, the wireless circuitry will oftenexhibit a blind spot near the device within which the wireless circuitryis unable to accurately detect the presence of external objects. Inaddition, it can be difficult for the wireless circuitry to fullycharacterize the location and orientation of external objects whenpresent within the blind spot.

SUMMARY

An electronic device may include wireless circuitry controlled by one ormore processors. The wireless circuitry may include a set of two or moreantennas communicably coupled to voltage standing wave ratio (VSWR)sensors. The VSWR sensors may gather VSWR measurements fromradio-frequency signals transmitted using the set of antennas. Theantennas in the set of antennas may be disposed on one or moresubstrates and/or may be formed from conductive portions of a housingfor the device. One or more processors may process the VSWR measurementsto identify the ranges between each of the antennas in the set ofantennas and an external object at, adjacent, or proximate to the set ofantennas. The one or more processors may process the ranges to identifyan angular location of the external object with respect to the device.

The one or more processors may perform any desired operations based onthe identified angular location. For example, the one or more processorsmay adjust subsequent communications by one or more of the antennasbased on the angular location (e.g., by reducing a maximum transmitpower level of one or more of the antennas). If desired, the one or moreprocessors may adjust the direction of a signal beam produced by aphased antenna array based on the angular location (e.g., to steer thesignal beam around the external object). As another example, the one ormore processors may identify a user input or gesture based on theangular location.

An aspect of the disclosure provides an electronic device operable in anenvironment that includes an external object. The electronic device caninclude a first antenna and a second antenna. The electronic device caninclude a first voltage standing wave ratio (VSWR) sensor communicablycoupled to the first antenna. The first VSWR sensor can be configured toperform a first VSWR measurement using radio-frequency signalstransmitted by the first antenna. The electronic device can include asecond VSWR sensor communicably coupled to the second antenna. Thesecond VSWR sensor can be configured to perform a second VSWRmeasurement using radio-frequency signals transmitted by the secondantenna. The electronic device can include one or more processors. Theone or more processors can be configured to identify a first range fromthe first antenna to the external object based on the first VSWRmeasurement. The one or more processors can be configured to identify asecond range from the second antenna to the external object based on thesecond VSWR measurement. The one or more processors can be configured toidentify an angular location of the external object based at least onthe first range and the second range.

An aspect of the disclosure provides a method for operating anelectronic device having a set of antennas, at least one voltagestanding wave ratio (VSWR) sensor communicably coupled to the set ofantennas, and one or more processors. The set of antennas can include atleast two antennas. The method can include with the set of antennas,transmitting radio-frequency signals. The method can include with the atleast one VSWR sensor, gathering VSWR measurements from theradio-frequency signals transmitted by different antennas in the set ofantennas. The method can include with the one or more processors,identifying a plurality of ranges between the set of antennas and theexternal object based on the VSWR measurements. The method can includewith the one or more processors, identifying an angular location of theexternal object based on the plurality of ranges between the set ofantennas and the external object.

An aspect of the disclosure provides a method of operating an electronicdevice in an environment having an external object. The method caninclude with a first antenna on the electronic device, transmittingfirst radio-frequency signals. The method can include with a secondantenna on the electronic device, transmitting second radio-frequencysignals. The method can include with a first voltage standing wave ratio(VSWR) sensor communicably coupled to the first antenna, gathering afirst VSWR measurement using the first radio-frequency signalstransmitted using the first antenna. The method can include with asecond VSWR sensor communicably coupled to the second antenna, gatheringa second VSWR measurement using the second radio-frequency signalstransmitted using the second antenna. The method can include with one ormore processors, identifying an angular location of the external objectbased at least on the first VSWR measurement and the second VSWRmeasurement. The method can include with the one or more processors,adjusting a subsequent transmission by the first antenna based at leaston the angular location of the external object.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram of an illustrative electronicdevice having voltage standing wave ratio (VSWR) sensors for detectingthe angular location of an external object in accordance with someembodiments.

FIG. 2 is a circuit diagram of an illustrative VSWR sensor having adirectional coupler for detecting the range between an external objectand an antenna in accordance with some embodiments.

FIG. 3 is a plot of reflection coefficient as a function of frequencythat may be produced by an illustrative VSWR sensor for detecting therange between an external object and an antenna in accordance with someembodiments.

FIG. 4 is a plot showing how the reflection coefficient measured by anillustrative VSWR sensor may vary at different times when externalobjects are present at different ranges from an antenna in accordancewith some embodiments.

FIG. 5 is a plot showing how reflection coefficient variation may becorrelated to the range between an antenna and an external object inaccordance with some embodiments.

FIG. 6 is a perspective view showing how an external object may bepresent at a given angular location over an electronic device surface inaccordance with some embodiments.

FIG. 7 is a flow chart of illustrative operations involved in detectingthe angular location of an external object using VSWR sensors andmultiple antennas in accordance with some embodiments.

FIG. 8 is a top view showing how multiple antennas may be used to detectthe angular location of an external object in accordance with someembodiments.

FIG. 9 is a side view showing how multiple antennas may be used todetect the angular location of an external object in accordance withsome embodiments.

FIG. 10 is a side view showing how multiple antennas may perform beamsteering operations based on the detected angular location of anexternal object in accordance with some embodiments.

FIG. 11 is a top view showing how antennas used to detect the angularlocation of an external object may be distributed across multiple arraysat different orientations in accordance with some embodiments.

FIG. 12 is a top view showing how antennas used to detect the angularlocation of an external object may be distributed across an electronicdevice in accordance with some embodiments.

DETAILED DESCRIPTION

Electronic device 10 of FIG. 1 may be a computing device such as alaptop computer, a desktop computer, a computer monitor containing anembedded computer, a tablet computer, a cellular telephone, a mediaplayer, or other handheld or portable electronic device, a smallerdevice such as a wristwatch device, a pendant device, a headphone orearpiece device, a device embedded in eyeglasses or other equipment wornon a user's head, or other wearable or miniature device, a television, acomputer display that does not contain an embedded computer, a gamingdevice, a navigation device, an embedded system such as a system inwhich electronic equipment with a display is mounted in a kiosk orautomobile, a wireless internet-connected voice-controlled speaker, ahome entertainment device, a remote control device, a gaming controller,a peripheral user input device, a wireless base station or access point,equipment that implements the functionality of two or more of thesedevices, or other electronic equipment.

As shown in the functional block diagram of FIG. 1 , device 10 mayinclude components located on or within an electronic device housingsuch as housing 12. Housing 12, which may sometimes be referred to as acase, may be formed of plastic, glass, ceramics, fiber composites, metal(e.g., stainless steel, aluminum, metal alloys, etc.), other suitablematerials, or a combination of these materials. In some situations,parts or all of housing 12 may be formed from dielectric or otherlow-conductivity material (e.g., glass, ceramic, plastic, sapphire,etc.). In other situations, housing 12 or at least some of thestructures that make up housing 12 may be formed from metal elements.

Device 10 may include control circuitry 14. Control circuitry 14 mayinclude storage such as storage circuitry 16. Storage circuitry 16 mayinclude hard disk drive storage, nonvolatile memory (e.g., flash memoryor other electrically-programmable-read-only memory configured to form asolid-state drive), volatile memory (e.g., static or dynamicrandom-access-memory), etc. Storage circuitry 16 may include storagethat is integrated within device 10 and/or removable storage media.

Control circuitry 14 may include processing circuitry such as processingcircuitry 18. Processing circuitry 18 may be used to control theoperation of device 10. Processing circuitry 18 may include on one ormore microprocessors, microcontrollers, digital signal processors, hostprocessors, baseband processor integrated circuits, application specificintegrated circuits, central processing units (CPUs), graphicsprocessing units (GPUs), etc. Control circuitry 14 may be configured toperform operations in device 10 using hardware (e.g., dedicated hardwareor circuitry), firmware, and/or software. Software code for performingoperations in device 10 may be stored on storage circuitry 16 (e.g.,storage circuitry 16 may include non-transitory (tangible) computerreadable storage media that stores the software code). The software codemay sometimes be referred to as program instructions, software, data,instructions, or code. Software code stored on storage circuitry 16 maybe executed by processing circuitry 18. If desired, portions of storagecircuitry 16 may be located on processing circuitry 18 (e.g., as L1 andL2 cache), whereas other portions of storage circuitry 16 are locatedexternal to processing circuitry 18 (e.g., while remaining accessible toprocessing circuitry 18 via a memory interface).

Control circuitry 14 may be used to run software on device 10 such assatellite navigation applications, internet browsing applications,voice-over-internet-protocol (VOIP) telephone call applications, emailapplications, media playback applications, operating system functions,etc. To support interactions with external equipment, control circuitry14 may be used in implementing communications protocols. Communicationsprotocols that may be implemented using control circuitry 14 includeinternet protocols, wireless local area network (WLAN) protocols (e.g.,IEEE 802.11 protocols—sometimes referred to as Wi-Fi®), protocols forother short-range wireless communications links such as the Bluetooth®protocol or other wireless personal area network (WPAN) protocols, IEEE802.11ad protocols (e.g., ultra-wideband protocols), cellular telephoneprotocols (e.g., 3G protocols, 4G (LTE) protocols, 3GPP Fifth Generation(5G) protocols, etc.), antenna diversity protocols, satellite navigationsystem protocols (e.g., global positioning system (GPS) protocols,global navigation satellite system (GLONASS) protocols, etc.),antenna-based spatial ranging protocols (e.g., radio detection andranging (RADAR) protocols or other desired range detection protocols forsignals conveyed at millimeter and centimeter wave frequencies), or anyother desired communications protocols. Each communications protocol maybe associated with a corresponding radio access technology (RAT) thatspecifies the physical connection methodology used in implementing theprotocol.

Device 10 may include input-output circuitry 20. Input-output circuitry20 may include input-output devices 22. Input-output devices 22 may beused to allow data to be supplied to device 10 and to allow data to beprovided from device 10 to external devices. Input-output devices 22 mayinclude user interface devices, data port devices, and otherinput-output components. For example, input-output devices 22 mayinclude touch sensors, displays (e.g., touch-sensitive and/orforce-sensitive displays), light-emitting components such as displayswithout touch sensor capabilities, buttons (mechanical, capacitive,optical, etc.), scrolling wheels, touch pads, key pads, keyboards,microphones, cameras, buttons, speakers, status indicators, audio jacksand other audio port components, digital data port devices, motionsensors (accelerometers, gyroscopes, and/or compasses that detectmotion), capacitance sensors, temperature sensors, proximity sensors,magnetic sensors, force sensors (e.g., force sensors coupled to adisplay to detect pressure applied to the display), etc. In someconfigurations, keyboards, headphones, displays, pointing devices suchas trackpads, mice, and joysticks, and other input-output devices may becoupled to device 10 using wired or wireless connections (e.g., some ofinput-output devices 22 may be peripherals that are coupled to a mainprocessing unit or other portion of device 10 via a wired or wirelesslink).

Input-output circuitry 20 may include wireless circuitry 24 to supportwireless communications and/or radio-based spatial ranging operations.Wireless circuitry 24 may include two or more antennas 40. Wirelesscircuitry 24 may also include baseband processor circuitry, transceivercircuitry, amplifier circuitry, filter circuitry, switching circuitry,analog-to-digital converter (ADC) circuitry, digital-to-analog converter(DAC) circuitry, radio-frequency transmission lines, and/or any othercircuitry for transmitting and/or receiving radio-frequency signalsusing antennas 40.

Antennas 40 may be formed using any desired antenna structures. Forexample, antennas 40 may include antennas with resonating elements thatare formed from loop antenna structures, patch antenna structures,inverted-F antenna structures, slot antenna structures, planarinverted-F antenna structures, helical antenna structures, monopoleantennas, dipoles, hybrids of these designs, etc. Filter circuitry,switching circuitry, impedance matching circuitry, and/or other antennatuning components may be adjusted to adjust the frequency response andwireless performance of antennas 40 over time.

Wireless circuitry 24 may use antennas 40 to transmit and/or receiveradio-frequency signals 38 to convey wireless communications databetween device 10 and external wireless communications equipment 28(e.g., one or more other devices such as device 10, a wireless accesspoint or base station, etc.). Wireless communications data may beconveyed by wireless circuitry 24 bidirectionally or unidirectionally.The wireless communications data may, for example, include data that hasbeen encoded into corresponding data packets such as wireless dataassociated with a telephone call, streaming media content, internetbrowsing, wireless data associated with software applications running ondevice 10, email messages, etc.

Wireless circuitry 24 may include communications and/or long rangespatial ranging circuitry 26 (sometimes referred to herein simply ascommunications circuitry 26). Communications circuitry 26 may transmitand/or receive wireless communications data using antennas 40.Communications circuitry 26 may include baseband circuitry (e.g., one ormore baseband processors) and one or more radios (e.g., radios havingradio-frequency transceivers, modems, synthesizers, switches, filters,mixers, ADCs, DACs, amplifiers, etc.) for conveying radio-frequencysignals 38 using one or more antennas 40.

Communications circuitry 26 may transmit and/or receive radio-frequencysignals 38 within a corresponding frequency band at radio frequencies(sometimes referred to herein as a communications band or simply as a“band”). The frequency bands handled by communications circuitry 26 mayinclude wireless local area network (WLAN) frequency bands (e.g., Wi-Fi®(IEEE 802.11) or other WLAN communications bands) such as a 2.4 GHz WLANband (e.g., from 2400 to 2480 MHz), a 5 GHz WLAN band (e.g., from 5180to 5825 MHz), a Wi-Fi® 6E band (e.g., from 5925-7125 MHz), and/or otherWi-Fi® bands (e.g., from 1875-5160 MHz), wireless personal area network(WPAN) frequency bands such as the 2.4 GHz Bluetooth® band or other WPANcommunications bands, cellular telephone frequency bands (e.g., bandsfrom about 600 MHz to about 5 GHz, 3G bands, 4G LTE bands, 5G New RadioFrequency Range 1 (FR1) bands below 10 GHz, 5G New Radio Frequency Range2 (FR2) bands between 20 and 60 GHz, etc.), other centimeter ormillimeter wave frequency bands between 10-300 GHz, near-fieldcommunications frequency bands (e.g., at 13.56 MHz), satellitenavigation frequency bands (e.g., a GPS band from 1565 to 1610 MHz, aGlobal Navigation Satellite System (GLONASS) band, a BeiDou NavigationSatellite System (BDS) band, etc.), ultra-wideband (UWB) frequency bandsthat operate under the IEEE 802.15.4 protocol and/or otherultra-wideband communications protocols, communications bands under thefamily of 3GPP wireless communications standards, communications bandsunder the IEEE 802.XX family of standards, and/or any other desiredfrequency bands of interest.

Communications circuitry 26 may be coupled to antennas 40 using one ormore transmit paths 34 and/or one or more receive paths 36.Communications circuitry 26 may uses transmit paths 34 to transmitradio-frequency signals 38 and may use receive paths 36 to receiveradio-frequency signals 38. Transmit paths 34 (sometimes referred toherein as transmit chains 34) may include one or more signal paths(e.g., radio-frequency transmission lines), amplifier circuitry, filtercircuitry, switching circuitry, radio-frequency front end circuitry(e.g., components on a radio-frequency front end module), and/or anyother desired paths or circuitry for transmitting radio-frequencysignals from communications circuitry 26 to antenna(s) 40. Receive paths36 may include one or more signal paths (e.g., radio-frequencytransmission lines), amplifier circuitry (e.g., low noise amplifier(LNA) circuitry), filter circuitry, switching circuitry, radio-frequencyfront end circuitry (e.g., components on a radio-frequency front endmodule), and/or any other desired paths or circuitry for conveyingradio-frequency signals from antenna(s) 40 to communications circuitry26.

In addition to conveying wireless communications data, communicationscircuitry 26 may additionally or alternatively use antennas 40 toperform long range spatial ranging operations. Communications circuitry26 may include long range spatial ranging circuitry for performing longrange spatial ranging operations. The long range spatial rangingcircuitry in communications circuitry 26 may include mixer circuitry,amplifier circuitry, transmitter circuitry (e.g., signal generators,synthesizers, etc.), receiver circuitry, filter circuitry, basebandcircuitry, ADC circuitry, DAC circuitry, and/or any other desiredcomponents used in performing spatial ranging operations using antennas40. The long range spatial ranging circuitry may include, for example,radar circuitry (e.g., frequency modulated continuous wave (FMCW) radarcircuitry, OFDM radar circuitry, FSCW radar circuitry, a phase codedradar circuitry, other types of radar circuitry). Antennas 40 mayinclude separate antennas for conveying wireless communications data andradio-frequency signals for spatial ranging or may include one or moreantennas 40 that are used to both convey wireless communications dataand to perform spatial ranging. Using a single antenna 40 to both conveywireless communications data and perform spatial ranging may, forexample, serve to minimize the amount of space occupied in device 10 byantennas 40.

When performing long range spatial ranging operations, the long rangespatial ranging circuitry in communications circuitry 26 may use a firstantenna 40 (e.g., a transmit antenna) to transmit radio-frequencysignals 42. Radio-frequency signals 42 may include one or more signaltones, continuous waves of radio-frequency energy, wideband signals,chirp signals, or any other desired transmit signals (e.g., radarsignals) for use in spatial ranging operations. Unlike radio-frequencysignals 38, radio-frequency signals 42 may be free from wirelesscommunications data (e.g., cellular communications data packets, WLANcommunications data packets, etc.). Radio-frequency signals 42 maysometimes also be referred to herein as spatial ranging signals 42, longrange spatial ranging signals 42, or radar signals 42. The long rangespatial ranging circuitry in communications circuitry 26 may transmitradio-frequency signals 42 at one or more carrier frequencies in acorresponding radio frequency band such (e.g., a frequency band thatincludes frequencies greater than around 10 GHz, greater than around 20GHz, less than 10 GHz, 20-30 GHz, greater than 40 GHz, etc.).

Radio-frequency signals 42 may reflect off of objects external to device10 such as external object 46. External object 46 may be, for example,the ground, a building, part of a building, a wall, furniture, aceiling, a person, a body part, an animal, a vehicle, a landscape orgeographic feature, an obstacle, external communications equipment suchas external wireless communications equipment 28, another device of thesame type as device 10 or a peripheral device such as a gamingcontroller or remote control, or any other physical object or entitythat is external to device 10. A second antenna 40 (e.g., a receiveantenna) in wireless circuitry 24 may receive reflected radio-frequencysignals 44. Reflected signals 44 may be a reflected version of thetransmitted radio-frequency signals 42 that have reflected off ofexternal object 46 and back towards device 10.

The long range spatial ranging circuitry in communications circuitry 26may receive reflected signals 44 from the second antenna 40 via acorresponding receive path 36. Control circuitry 14 may process thetransmitted radio-frequency signals 42 and the received reflectedsignals 44 to detect or estimate the range R between device 10 andexternal object 46. If desired, control circuitry 14 may also processthe transmitted and received signals to identify a two orthree-dimensional spatial location (position) of external object 46, avelocity of external object 46, and/or an angle of arrival of reflectedsignals 44. If desired, a loopback path may be coupled between thetransmit path 34 and the receive path 36 used by the long range spatialranging circuitry. The loopback path may be used to convey transmitsignals on the transmit path to receiver circuitry in the long rangespatial ranging circuitry. As an example, in embodiments where the longrange spatial ranging circuitry performs spatial ranging using an FMCWscheme, the loopback path may be a de-chirp path that conveys chirpsignals on the transmit path to a de-chirp mixer in the long rangespatial ranging circuitry. In these embodiments, doppler shifts incontinuous wave transmit signals may be detected and processed toidentify the velocity of external object 46, and the time dependentfrequency difference between radio-frequency signals 42 and reflectedsignals 44 may be detected and processed to identify range R and/or theposition of external object 46. Use of continuous wave signals forestimating range R may allow control circuitry 14 to reliablydistinguish between external object 46 and other background orslower-moving objects, for example. This example is merely illustrativeand, in general, the long range spatial ranging circuitry may implementany desired radar or long range spatial ranging scheme.

The radio-frequency transmission lines in transmit paths 34 and receivepaths 36 may include coaxial cables, microstrip transmission lines,stripline transmission lines, edge-coupled microstrip transmissionlines, edge-coupled stripline transmission lines, transmission linesformed from combinations of transmission lines of these types, etc.Transmission lines in device may be integrated into rigid and/orflexible printed circuit boards if desired. One or more radio-frequencylines may be shared between transmit path(s) 34 and receive path(s) 36if desired. The components of wireless circuitry 24 may be formed on oneor more common substrates or modules (e.g., rigid printed circuitboards, flexible printed circuit boards, integrated circuits, chips,packages, systems-on-chip, etc.).

The example of FIG. 1 is merely illustrative. While control circuitry 14is shown separately from wireless circuitry 24 in the example of FIG. 1for the sake of clarity, wireless circuitry 24 may include processingcircuitry that forms a part of processing circuitry 18 and/or storagecircuitry that forms a part of storage circuitry 16 of control circuitry14 (e.g., portions of control circuitry 14 may be implemented onwireless circuitry 24). As an example, some or all of the basebandcircuitry in communications circuitry 26 may form a part of controlcircuitry 14. The baseband processor circuitry may, for example, accessa communication protocol stack on control circuitry 14 (e.g., storagecircuitry 20) to: perform user plane functions at a PHY layer, MAClayer, RLC layer, PDCP layer, SDAP layer, and/or PDU layer, and/or toperform control plane functions at the PHY layer, MAC layer, RLC layer,PDCP layer, RRC, layer, and/or non-access stratum layer. If desired, thePHY layer operations may additionally or alternatively be performed byradio-frequency (RF) interface circuitry in wireless circuitry 24. Inaddition, wireless circuitry 24 may include any desired number ofantennas 40. Each antenna 40 may be coupled to communications circuitry26 over dedicated transmit and/or receive paths or over one or moretransmit and/or receive paths that are shared between antennas.Communications circuitry 26 may convey wireless communications datawithout performing spatial ranging operations (e.g., the long rangespatial ranging circuitry in communications circuitry 26 may be omitted)or communications circuitry 26 may perform spatial ranging operationswithout conveying wireless communications data.

The long range spatial ranging circuitry in communications circuitry 26may be used to accurately identify range R when external object 46 is atrelatively far distances from device 10. However, in practice, the longrange spatial ranging circuitry exhibits a blind spot to nearby externalobjects at distances less than threshold range R_(TH) (e.g., around 1-2cm) from device 10. When external object 46 is located within this blindspot (e.g., within threshold range R_(TH) from transmit antenna 40TX),the long range spatial ranging circuitry may be unable to identify thepresence, location, and/or velocity of external object 46 with asatisfactory level of accuracy. External objects 46 within thresholdrange R_(TH) of antenna(s) 40 may be exposed to relatively high amountsof radio-frequency energy (e.g., from the radio-frequency signals 38and/or 42 that are transmitted by antenna(s) 40). In scenarios whereexternal object 46 is a body part or person, if care is not taken, thistransmitted radio-frequency energy may cause wireless circuitry 24 toexceed regulatory limits or other limits on specific absorption rate(SAR) (e.g., when the transmitted signals are at frequencies below 6GHz) and/or maximum permissible exposure (MPE) (e.g., when thetransmitted signals are at frequencies above 6 GHz). In order to detectthe presence of external object 46 within threshold range R_(TH) fromantenna(s) 40, wireless circuitry 24 may include an ultra-short range(USR) object detector such as USR detector 30. USR detector 30 may serveto detect external object 46 at ultra-short ranges (e.g., at rangeswithin threshold range R_(TH) from antenna(s) 40). In other words, USRdetector 30 may perform external object detection within the blind spotof the long range spatial ranging circuitry in communications circuitry26.

USR detector 30 may include two or more voltage standing wave ratio(VSWR) sensors (detectors) such as VSWR sensors 32. Each VSWR sensor 32may be interposed on a respective transmit path 34. Each VSWR sensor 32may gather VSWR values using the antenna 40 coupled to its respectivetransmit path 34. The VSWR values may include complex scatteringparameter values (S-parameter values) such as reflection coefficient(return loss) values (e.g., S₁₁ values). The magnitude of the S₁₁ values(e.g., |S₁₁| values) may be indicative of the amount of transmittedradio-frequency energy that is reflected in a reverse direction alongthe transmit path (e.g., in response to the presence of external object46 at or adjacent to the corresponding antenna 40). The VSWR valuesgathered by each VSWR sensor 32 may be insensitive to situations whereexternal object 46 is located at distances greater than threshold rangeR_(TH) from antenna(s) 40. However, the VSWR values gathered by VSWRsensors 32 may allow control circuitry 14 to identify when externalobject 46 is located within threshold range R_(TH) from two or more ofthe antennas 40 in wireless circuitry 24 (e.g., within the blind spot ofthe long range spatial ranging circuitry in communications circuitry26).

In this way, USR detector 30 and the long range spatial rangingcircuitry may identify the presence of external object 46 and optionallythe range R to external object 46, regardless of whether external object46 has moved to a position that is relatively close or relatively farfrom device 10 over time. In addition, USR detector 30 may identify thepresence of external object 46 within the blind spot of the long rangespatial ranging circuitry in communications circuitry 26 so thatsuitable action can be taken to ensure that wireless circuitry 24continues to satisfy any applicable SAR and/or MPE regulations. By usingthe same antenna(s) 40 to both transmit radio-frequency signals 38/42and measure VSWR, the VSWR measurements will be very closely correlatedwith the amount of radio-frequency energy absorbed by external object 46from the transmitted radio-frequency signals 38/42, thereby providinghigh confidence in the use of USR detector 30 for meeting any applicableSAR and/or MPE regulations (e.g., greater confidence than in scenarioswhere proximity sensors that are separate from the transmit antenna ortransmit chain are used to identify the presence of external objectswithin threshold range R_(TH) of device 10).

In the example of FIG. 1 , two antennas 40 are illustrated as beingcommunicable coupled to respective VSWR sensors 32 in USR detector 30.In general, a set of any desired number N of two or more antennas 40 maybe communicably coupled to a respective VSWR sensor 32 (e.g., VSWRsensors 32 may be disposed/interposed on any desired number of two ormore of the transmit paths 34 in wireless circuitry 24). All of theantennas 40 may have a corresponding VSWR sensor 32 or only a subset ofthe antennas 40 may have a corresponding VSWR sensor 32. By using morethan one antenna 40 to gather (perform) VSWR measurements, controlcircuitry 14 may process the VSWR measurements to identify the range Rbetween external object 46 and each antenna 40 having a VSWR sensor 32.Control circuitry 14 may process the range R between external object 46and each of the antennas 40 having a VSWR sensor 32 to identify thelocation (e.g., the angular location) of external object 46 relative toa surface of device 10. Control circuitry 14 may use the identifiedangular location of external object 46 to perform any desired processingtasks, such as to perform beam steering using a phased antenna array ofantennas 40 (e.g., to steer around external object 46), to identify auser input or gesture corresponding to the angular location of externalobject 46, to adjust the maximum transmit power level for one or moreantennas 40, etc.

FIG. 2 is a circuit diagram of one of the VSWR sensors 32 in wirelesscircuitry 24 disposed on a corresponding transmit path 34. As shown inFIG. 2 , transmit path 34 may include a power amplifier (PA) such as PA96. The input of PA 96 may be coupled to communications circuitry 26 ofFIG. 1 . The output of PA 96 may be coupled to a corresponding antenna40 via a switch such as antenna switch 94. The output of PA 96 may alsobe coupled to matched load 88 via a switch such as matched load switch90. Matched load 88 may be coupled in series between matched load switch90 and ground 82. Matched load 88, matched load switch 90, and/orantenna switch 94 may be omitted if desired.

In the example of FIG. 2 , VSWR sensor 32 is a directional switchcoupler. This is merely illustrative and, in general, VSWR sensor 32 maybe implemented using any desired VSWR sensor architecture. As shown inFIG. 2 , VSWR sensor 32 may include directional coupler 72 interposed ontransmit path 34 between PA 96 and antenna 40 (e.g., along aradio-frequency transmission line in transmit path 34 coupled betweenthe output of PA 96 and antenna 40). Directional coupler 72 may have afirst port (P1) coupled to the output of PA 96 and a second port (P2)communicably coupled to antenna 40. Directional coupler 72 may have athird port (P3) coupled to a first termination that includes resistor 84coupled in series between termination switch 78 and ground 82.Directional coupler 72 may also have a fourth port (P4) coupled to asecond termination that includes resistor 86 coupled in series betweentermination switch 80 and ground 82. VSWR sensor 32 may have a forward(FW) switch 74 coupled between port P3 and measurement circuitry 70(e.g., an amplitude and/or phase detector). VSWR sensor 32 may also havea reverse (RW) switch 76 coupled between port P4 and measurementcircuitry 70.

Measurement circuitry 70 may have a control path coupled to othercomponents in USR detector 30 or control circuitry 14 (FIG. 1 ) and/orsome or all of measurement circuitry 70 may form a part of controlcircuitry 14 (e.g., the operations of some or all of measurementcircuitry 70 may be performed using one or more processors). Measurementcircuitry 70 may include, for example, a power detector such as powerdetector 98, an in-phase and quadrature-phase (I/Q) detector (e.g., anADC), logic such as comparator/logic 102 (e.g., one or more logic gates,etc.), and/or memory such as memory 104. Memory 104 may form a part ofstorage circuitry 16 of FIG. 1 , for example. If desired, I/Q detector100 may be formed from one or more ADCs in one of the receive paths 36of wireless circuitry 24 (FIG. 1 ).

When gathering (performing) VSWR measurements (e.g., S-parameter valuessuch as S₁₁ values), PA 96 may output a transmit test signal sigtx(e.g., while antenna switch 94 is closed). Test signal sigtx may be aradar transmit signal transmitted by long range spatial rangingcircuitry in communications circuitry 26 (e.g., radio-frequency signals42 of FIG. 1 ), a wireless communications data transmit signaltransmitted by communications circuitry 26 (e.g., radio-frequencysignals 38 of FIG. 1 ), or a dedicated test signal for use in VSWRmeasurement (e.g., one or more tones transmitted by a signal generator,local oscillator, and/or other signal generation circuitry in USRdetector 30 of FIG. 1 ). For example, a sequential signal generator 108may be used to generate test signal sigtx. Sequential signal generator108 may be a part of the long range spatial ranging circuitry incommunications circuitry 26 (e.g., test signal sigtx may be a continuouswave or wideband that can also be used in performing long range spatialranging operations), may be a part of a transceiver in communicationscircuitry 26 that transmits wireless communications data (e.g., testsignal sigtx may also carry wireless communications data), or may beformed as a part of USR detector 30 that is separate from communicationscircuitry 26. Additionally or alternatively, a simple local oscillatorsuch as local oscillator (LO) 106 may generate test signal sigtx.

In performing VSWR measurements, VSWR sensor 32 may perform forward pathmeasurements and reverse path measurements using transmit signal sigtx.When performing forward path measurements, FW switch 74 is closed, RWswitch 76 is open, switch 80 is closed, and switch 78 is open so thattest signal sigtx is coupled off from transmit path 34 by directionalcoupler 72 and routed to measurement circuitry 70 through FW switch 74.Measurement circuitry 70 may measure and store the amplitude (magnitude)and/or phase of test signal sigtx for further processing (e.g., as aforward signal phase and magnitude measurement). For example, powerdetector 98 (e.g., a peak detector, diode and capacitor, etc.) maymeasure the magnitude of test signal sigtx and may store the magnitudeon memory 104. As another example, I/Q detector 100 may make I/Qmeasurements for the forward path that are stored on memory 104.

At least some of test signal sigtx will reflect off of antenna 40 (e.g.,due to impedance discontinuities between transmit path 34 and antenna40, subject to impedance loading from any external objects at oradjacent to antenna 40) and back towards PA 96 as reflected test signalsigtx′. When performing reverse path measurements, FW switch 74 is open,RW switch 76 is closed, switch 80 is open, and switch 78 is closed sothat reflected test signal sigtx′ is coupled off of transmit path 34 bydirectional coupler 72 and routed to measurement circuitry 70 through RWswitch 76. Measurement circuitry 70 (e.g., power detector 98 or I/Qdetector 100) may measure and store the amplitude (magnitude) and/orphase of reflected test signal sigtx′ for further processing (e.g., as areverse signal phase and magnitude measurement). Comparator/logic 102and/or control circuitry 14 (FIG. 1 ) may process the stored forward andreverse phase and magnitude measurements to identify complex scatteringparameter values such as S₁₁ values. The S₁₁ values are characterized bya scalar magnitude |S₁₁| and a corresponding phase. In this way, VSWRsensor 32 may measure VSWR values (e.g., S₁₁ values, |S₁₁| values, etc.)that can be used to determine when external object 46 is located at arange R that is less than or equal to threshold range R_(TH). Long rangespatial ranging circuitry in communications circuitry 26 (FIG. 1 ) mayalso use antenna 40 to identify range R when external object 46 islocated at a range R that is beyond threshold range R_(TH) from antenna40.

If desired, control circuitry 14 may compare the VSWR measurements toone or more threshold values to identify range R. FIG. 3 is a plotshowing how VSWR measurements made by VSWR sensor 32 may be compared tomultiple threshold values to identify range R between external object 46and the corresponding antenna 40. Curve 110 plots the magnitude ofreflection S-parameter S₁₁ (i.e., |S₁₁|) as a function of frequency inthe absence of external object 46 within threshold range R_(TH). Asshown by curve 110, in the absence of external object 46, |S₁₁| may havea relatively high value across a frequency band of interest B.

Curve 112 plots |S₁₁| as a function of frequency when external object 46is within threshold range R_(TH) from antenna 40. As shown by curve 112,IS iii may have a relatively low value across frequency band B due tothe presence of external object 46. In general, once external object 46is within threshold range R_(TH), |S₁₁| will continue to decrease, asshown by arrow 114, as the object approaches the corresponding antenna40. Control circuitry 14 may gather VSWR values using VSWR sensor 32(e.g., IS ill values such as those shown by curves 110 and 112) and mayprocess the gathered VSWR values to identify range R when externalobject 46 is within threshold range R_(TH) (e.g., by comparing thegathered |S₁₁| values to one or more threshold levels TH).

For example, when the measured |S₁₁| value is less than a firstthreshold TH0, control circuitry 14 may determine (e.g., identify,deduce, estimate, etc.) that external object 46 is located at a firstrange R from antenna 40 (e.g., within threshold range R_(TH)), when themeasured |S₁₁| is value less than a second threshold TH1, controlcircuitry 14 may determine that external object 46 is located at asecond range R from antenna 40 that is closer than the first range, whenthe measured |S₁₁| value is less than a third threshold TH2, controlcircuitry 14 may determine that external object 46 is located at a thirdrange R from antenna 40 that is closer than the second range, etc.Beyond threshold range R_(TH), |S₁₁| will exhibit no change or anegligible change in response to changes in distance between antenna 40and external object 46. At these relatively far distances, the longrange spatial ranging circuitry in communications circuitry 26 (FIG. 1 )may be used to detect the presence, position (e.g., range R), and/orvelocity of external object 46.

The example of FIG. 3 in which control circuitry 14 identifies the rangeR between a given antenna 40 and external object 46 based on themagnitude of the VSWR measurements (e.g., |S₁₁| measurements) performedusing that antenna 40 is merely illustrative. Additionally oralternatively, control circuitry 14 may identify range R based on thephase of the S₁₁ measurements. Additionally or alternatively, controlcircuitry 14 may identify range R based on variations in the VSWRmeasurements over time.

FIG. 4 is a plot of different reflection coefficient (return loss)magnitude measurements (|S₁₁| values) that may be made by a given VSWRsensor 32 as a function of time in the presence an external object 46 atdifferent distances (ranges R) from the corresponding antenna 40. Points116 of FIG. 4 illustrate |S₁₁| measurements that may be made by VSWRsensor 32 at sampling times T0-T3 in the presence of an external object(e.g., an animate object) at a first range R from antenna 40 (e.g.,within threshold range R_(TH)). The external object may be, for example,a body part such as a hand, finger, or head. As shown by points 116,there is a relatively high amount of variation in |S₁₁| as a function oftime in the presence of the external object at the first range R fromantenna 40 (e.g., due to minute movements of the external objectrelative to static/inanimate objects such as a removable device case).Points 118 illustrate |S₁₁| measurements that may be made by VSWR sensor32 at times T0-T3 in the presence of the external object at a secondrange R from antenna 40 that is closer than the first range. As shown bypoints 118, there is even more variation in |S₁₁| as a function of timein the presence of the external object at the second range R fromantenna 40 (e.g., because minute movements of the external objectproduce a greater variation in the impedance loading of antenna 40 andthus the gathered VSWR measurements at closer ranges).

Control circuitry 14 may identify (e.g., detect, produce, compute,calculate, estimate, etc.) variations in the |S₁₁| measurements overtime to identify the range between antenna 40 and the external object(e.g., by comparing the identified variation to one or more thresholdvariation levels). Control circuitry 14 may perform range detection inthis way based on any desired metric for the variation of VSWR (e.g.,|S₁₁|) measurements over time. For example, control circuitry 14 mayperform range detection based on the difference between the maximum|S₁₁| value and the minimum |S₁₁| value measured at each of the samplingtimes. For points 116, control circuitry 14 may identify (e.g., compute,calculate, generate, determine, etc.) a first difference value Δ1 thatis equal to the difference between the maximum |S₁₁| value B of points116 (e.g., as measured at time T1) and the minimum |S₁₁| value C ofpoints 116 (e.g., as measured at time T2). Similarly, for points 118,control circuitry 14 may identify a second difference value Δ2 that isequal to the difference between the maximum |S₁₁| value A of points 116(e.g., as measured at time T1) and the minimum |S₁₁| value D of points118 (e.g., as measured at time T0). Difference value Δ2 is greater thandistance value Δ1 and is therefore indicative of external object 46being located at a closer range to antenna 40 than when distance valueΔ1 is measured.

The example of FIG. 4 is merely illustrative. Points 116 and 118 mayhave other values in practice. In the example of FIG. 4 , four samplingtimes T0-T3 are used to identify variations in |S₁₁| for performinganimate object detection. This is merely illustrative and, in general,any desired number of sampling times may be used to identify variationsin |S₁₁| for performing animate object detection. Each sampling time maybe separated by 10 ms, 20 ms, 1-20 ms, more than 20 ms, 10-50 ms, or anyother desired period. The sampling times need not be evenly spaced.

Curve 120 of FIG. 5 shows one example of how variation in |S₁₁| may becorrelated with the range between external object 46 and antenna 40. Ifdesired, control circuitry 14 may compare the identified variation inthe VSWR measurements (e.g., difference value Δ) to curve 120 toidentify the corresponding range R between external object 46 andantenna 40. As shown by curve 120, control circuitry 14 may determinethat external object 46 is located at first range R1 when differencevalue Δ1 is measured (e.g., by identifying the horizontal coordinate oncurve 120 corresponding to difference value Δ1) and may determine thatthat external object 46 is located at second range R2 when differencevalue Δ2 is measured. This is merely illustrative and, if desired,control circuitry 14 may identify range R by comparing the measureddifference value Δ to one or more threshold difference values, bycomparing difference value Δ to entries in a lookup table, database, orother data structure, etc. Curve 120 may be stored on device 10 (e.g.,during factory calibration, manufacture, assembly, testing, etc.). Theexample of FIG. 5 is merely illustrative and, in practice, curve 120 mayhave other shapes.

The example of FIGS. 4 and 5 is merely illustrative and, in general,control circuitry 14 may identify any desired metric of variance in|S₁₁| for comparison to one or more threshold values in identifying therange R between external object 46 and antenna 40. As other examples,control circuitry 14 may identify the mean and variance of the |S₁₁|measurements over time, the rate of change of |S₁₁| measurements overtime, and/or any other desired variation metrics for comparison to oneor more threshold values for identifying range R.

In summary, control circuitry 14 may use VSWR measurements (e.g., |S₁₁|values) measured using VSWR sensor 32 or variations in the VSWRmeasurements (e.g., variations in the |S₁₁| values over time)gathered/performed using VSWR sensor 32 to detect (e.g., identify,determine, estimate, compute, calculate, deduce, etc.) the range Rbetween external object 46 and the corresponding antenna 40. Controlcircuitry 14 may process the range R between external object 46 and eachantenna 40 in the set of N antennas 40 having a corresponding VSWRsensor 32 to identify the angular location of external object 46.

FIG. 6 illustrates one example of how the angular location of externalobject 46 may be defined. External object 46 is illustrated as a humanfinger herein as an example. This is merely illustrative and, ingeneral, external object 46 may be other body parts of the user ofdevice 10, other humans or animals, furniture, walls, ceilings, theground, a peripheral device or accessory such as a gaming controller,user interface/input device, or headset, and/or any other objectexternal to device 10.

In the example of FIG. 6 , the control circuitry on device 10 (e.g.,control circuitry 14 of FIG. 1 ) uses a spherical coordinate system todetermine the location and orientation of external object 46 relative toa (lateral) surface 122 of device 10. Surface 122 may, for example, be asurface of a housing wall for device 10 (e.g., housing 12 of FIG. 1 ), asurface of a cover layer for device 10 (e.g., a dielectric cover layer),a surface of a display on or mounted to the housing, the surface of anantenna module on or within device 10, or any other desired surface on,at, or within device 10. Surface 122 need not be planar.

In this type of coordinate system, control circuitry 14 may process therange R between two or more antennas 40 (e.g., as identified using VSWRmeasurements gathered using the two or more antennas as described abovein connection with FIGS. 2-5 ) to determine (e.g., calculate, compute,detect, estimate, deduce, generate, etc.) an azimuth angle θ and/or anelevation angle φ that characterize (identify) the angular location ofexternal object 46 relative to a point P on surface 122 (or some otherreference surface). When viewed in the −Z direction, point P may belaterally located between two or more of the antennas 40 in device 10having a corresponding VSWR sensor 32 (for example).

In identifying the angular location of external object 46 (e.g., aspherical coordinate value (θ, φ), sometimes referred to herein asangle-of-arrival), control circuitry 14 may define a reference plane atlateral surface 122 and a reference vector such as reference vector 126.Reference vector 126 may lie within the reference plane (e.g., lateralsurface 122).

As shown in FIG. 6 , external object 46 may be separated from point P byrange R (e.g., where range R is the magnitude of a positional vectorextending from point P to external object 46). The elevation angle φ(sometimes referred to as altitude) of external object 46 may bemeasured as the angle between the positional vector extending from pointP to external object 46 and the reference plane (e.g., lateral surface122). The azimuth angle θ of external object 46 may be measured as theangle of external object 46 around the reference plane (e.g., the anglebetween reference vector 126 and vector 128, which is the horizontalprojection of the positional vector extending from point P to externalobject 46 within the reference plane). In the example of FIG. 6 , theazimuth angle θ and elevation angle φ of external object 46 are eachgreater than 0°.

If desired, other axes may be used to define reference vector 126 (e.g.,reference vector 126 may point in any direction). Other angles may beused to characterize the angular location of external object 46 (e.g.,the angle between the normal vector (axis) 124 of surface 122 and thepositional vector extending from point P to external object 46, which isequal to 90°−φ, other angles, etc.). The example of FIG. 6 in which theangular position of external object 46 is characterized using sphericalcoordinates (e.g., as an angular position (θ, φ)) is merelyillustrative. In general, control circuitry 14 may characterize oridentify the angular location of external object 46 using any desiredcoordinate system (e.g., rectangular/Cartesian coordinates, polarcoordinates, cylindrical coordinates, other coordinate systems, etc.)about any desired reference axes. The reference plane may be arbitrarilyselected if desired and need not coincide with the presence of a surfaceof device 10 such as surface 122.

FIG. 7 is a flow chart of illustrative operations that may be performedby device 10 to identify the angular location of external object 46using VSWR values gathered using multiple antennas 40 on device 10(e.g., a set of N antennas 40 each having a respective VSWR sensor 32communicatively coupled thereto along a respective transmit path 34).The number N may be two, three, four, five, six, seven, eight, or morethan eight, as examples. Each of the N antennas 40 may be disposed atdifferent points on/across device 10.

At operation 130, control circuitry 14 may control wireless circuitry 24to transmit test signals sigtx (FIG. 2 ) over each of the N antennas 40.Test signals sigtx may be transmitted over each of the N antennas 40concurrently (e.g., simultaneously) or sequentially (in series). Testsignals sigtx may be transmitted at a single carrier frequency or over arange/sweep of frequencies. The N antennas 40 may begin transmittingtest signals sigtx once one or more of the VSWR sensors 32 has alreadydetected that external object 46 has passed within threshold rangeR_(TH) of the corresponding antenna 40 or in response to any desiredtrigger condition (e.g., an application or software call on controlcircuitry 14, once VSWR measurements such as |S₁₁| measurements reach apredetermined threshold value, etc.).

As another example, the control circuitry 14 may perform operation 130once device 10 has determined that gathered wireless performance metricdata has fallen outside of a predetermined range. In this example,wireless circuitry 24 may gather wireless performance metric dataassociated with the radio-frequency performance of antenna(s) 40. Thewireless performance metric data may include signal-to-noise ratio (SNR)data, receive signal strength indicator (RSSI) data, or any otherdesired performance metric data gathered during the transmission ofradio-frequency signals 38, the transmission of radio-frequency signals42, the reception of radio-frequency signals 38, and/or the reception ofreflected signals 44 of FIG. 1 , for example. Control circuitry 14 maycompare the gathered wireless performance metric data with apredetermined range of wireless performance metric values associatedwith satisfactory radio-frequency performance and/or the operation ofwireless circuitry 24 in the absence of external objects withinthreshold range R_(TH) (e.g., a predetermined range of satisfactory RSSIvalues, SNR values, etc.). The predetermined range of wirelessperformance metric values may be characterized by an upper thresholdlimit or value and/or a lower threshold limit or value.

In this example, the wireless performance metric data may serve as acoarse indicator for whether external object 46 is within thresholdrange R_(TH). For example, if external object 46 is within range R_(TH),external object 46 may partially block or cover one or more antennas 40(thereby preventing the antenna from properly receiving radio-frequencysignals), may undesirably load or detune one or more antennas 40 indevice 10, etc. When the gathered wireless performance metric data fallsoutside of the predetermined range, this may be indicative of thepotential presence of external object 46 within threshold range R_(TH).However, when the gathered wireless performance metric data falls withinthe predetermined range, this may indicate that it is very unlikely thatthere is an external object present within threshold range R_(TH) (e.g.,because wireless circuitry 24 is performing nominally as expected in theabsence of an external object within threshold range R_(TH)). If thegathered wireless performance metric data falls within the predeterminedrange (thereby indicating that there is no external object withinthreshold range R_(TH)), VSWR sensor(s) 32 may gather background VSWRmeasurements for performing background cancellation if desired. Ingeneral, operation 130 may be performed in response to any desiredtrigger condition.

At operation 132, control circuitry 14 may use the respective VSWRsensor 32 (e.g., measurement circuitry 70 of FIG. 2 ) coupled to each ofthe N antennas 40 to perform at least N VSWR measurements (e.g., S₁₁values, |S₁₁| values, time-variations in the |S₁₁| values such asdifference values Δ of FIGS. 4 and 5 , etc.) for each of the N antennas40 using the transmitted test signals sigtx. Control circuitry 14 mayperform the VSWR measurements for each of the N antennas 40 concurrently(e.g., when the N antennas 40 transmit test signals sigtx concurrently)or sequentially (e.g., when the N antennas 40 transmit test signalssequentially). Operation 132 may, for example, be performed concurrentlywith operation 130. In examples where the VSWR measurements areperformed sequentially, two or more (e.g., all) of the N antennas 40 mayshare a single transmit path 34 and VSWR sensor 32 if desired.

At operation 134, control circuitry 14 may process the VSWR measurementsfor each of the N antennas 40 to identify (e.g., determine, detect,estimate, calculate, compute, deduce, etc.) the respective range Rbetween each of the N antennas 40 and external object 46. Controlcircuitry 14 may identify ranges R by comparing the VSWR measurements toone or more threshold values. For example, control circuitry 14 mayidentify ranges R by comparing |S₁₁| values gathered using each of the Nantennas 40 to threshold values TH of FIG. 3 , by comparing differencevalues Δ of FIG. 4 to one or more threshold values or to curve 120 ofFIG. 5 , by comparing the phases of the VSWR measurements to one or morethreshold values, etc. Control circuitry 14 need not use the same methodto calculate VSWR for each of the N antennas 40 (e.g., control circuitry14 may identify range R using variations in the VSWR measurements overtime for some of the N antennas 40 while identifying range R using |S₁₁|values for others of the N antennas 40, etc.).

If desired, control circuitry 14 may identify range R while alsoperforming VSWR background cancellation. For example, control circuitry14 may use the VSWR sensor(s) 32 to gather background VSWR measurementsin the absence of other external objects within threshold range R_(TH)from the corresponding antenna(s) 40 (e.g., where the background VSWRmeasurements also take into account the presence of the removable devicecase). Control circuitry 14 may then use the background VSWRmeasurements to perform background cancellation on subsequent VSWRmeasurements (e.g., as performed at operation 132) that are gathered inthe presence of external object 46 within threshold range R_(TH) (e.g.,by subtracting the background VSWR measurements from the subsequent VSWRmeasurements).

At operation 136, control circuitry 14 may process each of the Nidentified ranges R (e.g., the range R identified between each of the Nantennas 40 and external object 46) to identify (e.g., determine,calculate, estimate, deduce, generate, triangulate, resolve, etc.) theangular location of external object 46 relative to surface 122 of device10 (FIG. 6 ) or any other desired reference plane. Control circuitry 14may identify the angular location of external object 46 (e.g., a point(θ, φ) in spherical coordinates or any other desired coordinate system)by performing geometric calculations based on (using) the identifiedranges R between the N antennas 40 and external object 46 and the known(predetermined) separation/spacing between each of the N antennas. Eachrange R may, for example, be the radius of a sphere of potentiallocations for device 10 centered on the corresponding antenna 40.Control circuitry 14 may identify the location of external object 46 asthe location/point where each of the N spheres intersect in space.Control circuitry 14 may then identify the angular location of externalobject 46 as the angle of a vector extending from any desired point onlateral surface 122 (e.g., point P of FIG. 6 ) to the location/pointwhere each of the N spheres intersect in space (e.g., angles relative toany desired vectors such as vectors 126, 128, and/or 124 of FIG. 6 orother vectors and in any desired coordinate system). In sphericalcoordinates, this angle may be characterized by a spherical point (θ,φ), for example. Additionally or alternatively, control circuitry 14 mayidentify the angular location using a lookup table, database, or otherdata structure that maps different range values R for each of the Nantennas to different angular locations for external object 46 (in anydesired angular coordinate system about any desired reference points orreference vectors). The lookup table, database, or other data structuremay be populated during design, manufacture, assembly, testing, orcalibration of device 10 and/or may be populated/updated duringoperation of device 10 by an end user.

At operation 138, control circuitry 14 may perform any desiredprocessing operations based on the identified angular location ofexternal object 46. For example, at operation 140, control circuitry 14may adjust the transmit power level or maximum transmit power level ofone or more of the antennas 40 on device 10 based on the angularlocation of external object 46 (e.g., control circuitry 14 may increasethe transmit power level or the maximum transmit power level of antennas40 that are relatively far from external object 46 and/or may decreasethe transmit power level or maximum transmit power level of antennas 40that are relatively close to external object 46). If desired, controlcircuitry 14 may disable or activate antennas 40 based on the identifiedangular location (e.g., control circuitry 14 may switch antennas 40 thatare too close to external object 46 out of use). These techniques may,for example, help to ensure that device 10 continues to satisfyregulatory limits on radio-frequency energy exposure (e.g., SAR/MPElimits).

As another example, at operation 142, control circuitry 14 may adjustthe angle of a signal beam produced by a phased antenna array of theantennas 40 in device 10 (e.g., the N antennas 40 used to gather VSWRmeasurements and/or other antennas 40) based on the identified angularlocation of external object 46. For example, control circuitry 14 mayadjust (steer) the signal beam around the identified angular location(e.g., to point the signal beam in a different angle than the identifiedangular location). This may prevent the signal beam from overlapping theexternal object, thereby helping device 10 to satisfy regulatory limitson radio-frequency energy exposure while also allowing device 10 tocontinue to perform wireless operations over the signal beam without theexternal object blocking the signal beam.

As yet another example, at operation 144, control circuitry 14 mayidentify a user input action such as a gesture action based on theidentified angular location. Control circuitry 14 may identify aparticular user input or gesture corresponding to the identified angularlocation and/or corresponding to particular changes in angular locationof external object 46 over time (e.g., over multiple iterations ofoperations 130-136 of FIG. 7 ). The user input or gesture may, forexample, form a user input used by software applications running ondevice 10 to perform any desired processing tasks, operations, orfunctions. The gestures may, for example, be used to control, perform,or coordinate on-screen actions displayed on a display for device 10using the software applications.

The example of FIG. 7 is merely illustrative. Operations 140, 142,and/or 144 may be omitted. Control circuitry 14 may perform any otherdesired processing operations or device functions based on theidentified angular location of external object 46 and/or the identifiedangular location of external object 46 over time (e.g., over multipleiterations of the operations of FIG. 7 ).

FIG. 8 is a top view showing one example of how N=4 antennas 40 may beused to identify the angular location of external object 46. In theexample of FIG. 8 , antennas 40-1, 40-2, 40-3, and 40-4 may each becoupled to a respective transmit path 34 having a respective VSWR sensor32. In examples where the N antennas gather VSWR measurementssequentially, two or more of the antennas may share a single transmitpath 34 and VSWR sensor 32. Antennas 40-1, 40-2, 40-3, and/or 40-4 mayalso be used to convey wireless communications data and/or to performlong range spatial ranging for communications circuitry 26 of FIG. 1 .If desired, some or all of antennas 40-1, 40-2, 40-3, and 40-4 may formpart of a phased antenna array (e.g., antennas 40-1, 40-2, 40-3, and40-4 may be a four-element phased antenna array).

As shown in FIG. 8 , antennas 40-1, 40-2, 40-3, and 40-4 may be formedon or within a substrate such as substrate 146. Substrate 146 may be aprinted circuit such as a rigid printed circuit board or flexibleprinted circuit, may be a plastic, ceramic, or glass substrate, may be ahousing wall or cover layer for device 10, may be a portion of a displayfor device 10, or may be any other desired dielectric material. Thisexample is merely illustrative and, if desired, each antenna may bedisposed on a respective substrate 146, the antennas may be dividedbetween two or more substrates 146, or one or more of the antennas maybe disposed in device 10 without a substrate. The uppermost surface ofsubstrate 146 may, for example, form surface 122 of FIG. 6 .

During angular detection operations, antennas 40-1, 40-2, 40-3, and 40-4may each transmit test signals sigtx (e.g., while processing operation130 of FIG. 7 ). The VSWR sensor(s) 32 coupled to antennas 40-1, 40-2,40-3, and 40-4 may perform VSWR measurements using the test signalssigtx transmitted by each of the antennas (e.g., while processingoperation 132 of FIG. 7 ). Control circuitry 14 may process the VSWRmeasurement(s) performed using antenna to identify the range R1 betweenantenna 40-1 and external object 46, may process the VSWR measurement(s)performed using antenna 40-2 to identify the range R2 between antennaand external object 46, may process the VSWR measurement(s) performedusing antenna to identify the range R3 between antenna 40-3 and externalobject 46, and may process the VSWR measurement(s) performed usingantenna 40-4 to identify the range R4 between antenna and externalobject 46.

The top view of FIG. 8 shows the lateral projections of ranges R1-R4 inthe X-Y plane. FIG. 9 is a side view of the antennas 40-1, 40-2, 40-3,and 40-4 on substrate 146 (e.g., as taken in the direction of arrow 148of FIG. 8 ). FIG. 9 shows the projections of ranges R1-R4 in the X-Zplane (e.g., ranges R1-R4 may be the magnitudes of three-dimensionalposition vectors extending from antennas 40-1, 40-2, 40-3, and 40-4 toexternal object 46, respectively). Range R1 may correspond to the radiusof a sphere of potential locations for external object 46 that iscentered on antenna 40-1. Range R2 may correspond to the radius of asphere of potential locations for external object 46 that is centered onantenna 40-2. Range R3 may correspond to the radius of a sphere ofpotential locations for external object 46 that is centered on antenna40-3. Range R4 may correspond to the radius of a sphere of potentiallocations for external object 46 that is centered on antenna 40-4.

Control circuitry 14 may process ranges R1-R4 to identify the angularlocation of external object 46 while processing operation 136 of FIG. 7(e.g., by identifying the angular position of the point/location whereeach of the spheres corresponding to ranges R1-R4 intersect, bycomparing ranges R1-R4 to a lookup table of angular locations, etc.).For example, control circuitry 14 may identify the angle θ at point P toexternal object 46 relative to reference vector 126 (FIG. 8 ) and theangle φ at point P to external object 46 relative to the lateral surfaceof substrate 146 (e.g., lateral surface 122 of FIG. 6 ) in sphericalcoordinates. Point P may be located between (e.g., equidistant from)antennas 40-1, 40-2, 40-3, and 40-4 or may be at any other desiredlocation on the lateral surface of substrate 146. This is merelyillustrative and, in general, control circuitry 14 may identify theangular location of external object 46 using any desired coordinatesystem and with respect to any desired location (e.g., point P) ondevice 10. The example of FIGS. 8 and 9 in which N=4 antennas 40 areused to identify the angular location of external object 46 is merelyillustrative and, in general, N may have other values greater than two.The N antennas may be arranged in any desired pattern (e.g., in atwo-dimensional array pattern, a one-dimensional array pattern, apattern of concentric rings, etc.) and may be formed using any desiredtype of antenna resonating elements.

FIG. 10 is a side view showing how the angular location of externalobject 46 may be used to perform beam steering operations (e.g., whileprocessing operation 142 of FIG. 7 ). As shown in FIG. 10 , device 10may include a phased antenna array 156 (sometimes referred to herein asarray 156, antenna array 156, or array 156 of antennas 40). Phasedantenna array 156 may include M antennas 40 such as a first antenna40-1, an Mth antenna 40-M, etc. The antennas in phased antenna array 156may be disposed on substrate 146, on another substrate, or may bedistributed across two or more substrates. Phased antenna array 156 maybe coupled to radio-frequency transmission line paths 150 (e.g.,radio-frequency transmission line paths used to form transmit path(s) 34and/or receive path(s) 36 of FIG. 1 ). For example, a first antenna 40-1in phased antenna array 156 may be coupled to a first radio-frequencytransmission line path 150-1, an Mth antenna 40-M in phased antennaarray 156 may be coupled to an Mth radio-frequency transmission linepath 150-M, etc. Some, none, or all of the M antennas in phased antennaarray 40 may be among the N antennas 40 used to identify the angularlocation of external object 46. While antennas 40 are described hereinas forming a phased antenna array, the antennas 40 in phased antennaarray 156 may sometimes also be referred to as collectively forming asingle phased array antenna (e.g., where each antenna 40 in the phasedarray antenna forms an antenna element or radiator of the phased arrayantenna).

Radio-frequency transmission line paths 150 may each be coupled totransceiver circuitry such as a 5G NR transceiver in communicationscircuitry 26 of FIG. 1 . Each radio-frequency transmission line path 150may include one or more radio-frequency transmission lines, a positivesignal conductor, and a ground signal conductor. The positive signalconductor may be coupled to a positive antenna feed terminal on anantenna resonating element of the corresponding antenna 40. The groundsignal conductor may be coupled to a ground antenna feed terminal on anantenna ground for the corresponding antenna 40.

The antennas 40 in phased antenna array 156 may be arranged in anydesired number of rows and columns or in any other desired pattern(e.g., the antennas need not be arranged in a grid pattern having rowsand columns). During signal transmission operations, radio-frequencytransmission line paths 150 may be used to supply signals (e.g.,radio-frequency signals such as millimeter wave and/or centimeter wavesignals) from the transceiver in communications circuitry 26 (FIG. 1 )to phased antenna array 156 for wireless transmission. During signalreception operations, radio-frequency transmission line paths 150 may beused to convey signals received at phased antenna array 156 (e.g., fromexternal wireless equipment 28 of FIG. 1 ) to the transceiver incommunications circuitry 26.

The use of multiple antennas 40 in phased antenna array 156 allowsradio-frequency beam forming arrangements (sometimes referred to hereinas radio-frequency beam steering arrangements) to be implemented bycontrolling the relative phases and magnitudes (amplitudes) of theradio-frequency signals conveyed by the antennas. In the example of FIG.10 , the antennas 40 in phased antenna array 156 each have acorresponding radio-frequency phase and magnitude controller 152 (e.g.,a first phase and magnitude controller 152-1 interposed onradio-frequency transmission line path 150-1 may control phase andmagnitude for radio-frequency signals handled by antenna 40-1, an Mthphase and magnitude controller 152-M interposed on radio-frequencytransmission line path 150-M may control phase and magnitude forradio-frequency signals handled by antenna 40-M, etc.).

Phase and magnitude controllers 152 may each include circuitry foradjusting the phase of the radio-frequency signals on radio-frequencytransmission line paths 150 (e.g., phase shifter circuits) and/orcircuitry for adjusting the magnitude of the radio-frequency signals onradio-frequency transmission line paths 150 (e.g., power amplifierand/or low noise amplifier circuits). Phase and magnitude controllers152 may sometimes be referred to collectively herein as beam steering orbeam forming circuitry (e.g., beam steering circuitry that steers thebeam of radio-frequency signals transmitted and/or received by phasedantenna array 156).

Phase and magnitude controllers 152 may adjust the relative phasesand/or magnitudes of the transmitted signals that are provided to eachof the antennas in phased antenna array 156 and may adjust the relativephases and/or magnitudes of the received signals that are received byphased antenna array 156. Phase and magnitude controllers 152 may, ifdesired, include phase detection circuitry for detecting the phases ofthe received signals that are received by phased antenna array 156. Theterm “beam,” “signal beam,” “radio-frequency beam,” or “radio-frequencysignal beam” may be used herein to collectively refer to wirelesssignals that are transmitted and received by phased antenna array 156 ina particular direction. The signal beam may exhibit a peak gain that isoriented in a particular beam pointing direction at a corresponding beampointing angle (e.g., based on constructive and destructive interferencefrom the combination of signals from each antenna in the phased antennaarray). The term “transmit beam” may sometimes be used herein to referto radio-frequency signals that are transmitted in a particulardirection whereas the term “receive beam” may sometimes be used hereinto refer to radio-frequency signals that are received from a particulardirection.

If, for example, phase and magnitude controllers 152 are adjusted toproduce a first set of phases and/or magnitudes for transmittedradio-frequency signals, the transmitted signals will form a transmitbeam that is oriented in a first direction such as the direction ofexternal object 46. If, however, phase and magnitude controllers 152 areadjusted to produce a second set of phases and/or magnitudes for thetransmitted signals, the transmitted signals will form a transmit beamas shown by beam 160 that is oriented in direction 158, which pointsaway from external object 46. Similarly, if phase and magnitudecontrollers 152 are adjusted to produce the first set of phases and/ormagnitudes, radio-frequency signals (e.g., radio-frequency signals in areceive beam) may be received from the direction external object 46. Ifphase and magnitude controllers 152 are adjusted to produce the secondset of phases and/or magnitudes, radio-frequency signals may be receivedfrom direction 158, as shown by beam 160.

Each phase and magnitude controller 152 may be controlled to produce adesired phase and/or magnitude based on a corresponding control signal154 received from control circuitry 14 of FIG. 1 (e.g., the phase and/ormagnitude provided by phase and magnitude controller 152-1 may becontrolled using control signal 154-1, the phase and/or magnitudeprovided by phase and magnitude controller 152-M may be controlled usingcontrol signal 154-M, etc.). If desired, control circuitry 14 mayactively adjust control signals 154 in real time to steer the transmitor receive beam in different desired directions (e.g., to differentdesired beam pointing angles) over time. In the example of FIG. 10 ,beam steering is shown as being performed over a single degree offreedom for the sake of simplicity (e.g., towards the left and right onthe page of FIG. 10 ). However, in practice, the beam may be steeredover two or more degrees of freedom (e.g., in three dimensions, into andout of the page and to the left and right on the page of FIG. 10 ) or ina single degree of freedom (e.g., when the antennas 40 in phased antennaarray are arranged in a one-dimensional pattern). Phased antenna array156 may have a corresponding field of view over which beam steering canbe performed (e.g., in a hemisphere or a segment of a hemisphere overthe phased antenna array). If desired, device 10 may include multiplephased antenna arrays that each face a different direction to providecoverage from multiple sides of the device.

While processing operation 136 of FIG. 7 , control circuitry 14 maydetermine that external object 46 is at direction (angular location) Jwith respect to phased antenna array 156. While processing operation 142of FIG. 7 , control circuitry 14 may adjust phase and magnitudecontrollers 152 to steer signal beam 160 in direction 158 (e.g., awayfrom direction J) so the signal beam does not overlap external object46. This may help to ensure that phased antenna array 156 continues tocomply with regulations on RF exposure and/or to ensure that phasedantenna array 156 is able to convey wireless communications data and/orperform spatial ranging operations despite the presence of externalobject 46 in proximity to phased antenna array 156.

If desired, the N antennas 40 used to identify the angular location ofexternal object 46 may be distributed across two or more substrates.FIG. 11 is a top view of device 10 showing one example of how the Nantennas 40 may be distributed across two substrates.

As shown in FIG. 11 , the N antennas 40 used to identify the angularlocation of external object 46 may include a first set of antennas 40 ona first substrate 146A and a second set of antennas 40 on a secondsubstrate 146B disposed within housing 12 of device 10. The first set ofantennas may, for example, be arranged in a one-dimensional pattern onsubstrate 146A whereas the second set of antennas are arranged in aone-dimensional pattern on substrate 146B. Because a singleone-dimensional array of antennas may be insufficient to fully resolveambiguities in the angular location of external object 46, the secondset of antennas 40 on substrate 146B may be oriented perpendicular tothe first set of antennas 40 on substrate 146A (e.g., the antennas 40 onsubstrate 146A may be disposed along a first axis, the antennas 146B maybe disposed along a second axis, and the second axis may be orientedperpendicular to the first axis). The first and the second sets ofantennas may then be able to resolve the correct angular location ofexternal object 46. The first set of antennas 40 and the second set ofantennas 40 may radiate through a rear face of device 10 (e.g., a faceof device 10 opposite to a display for device 10) or may radiate throughthe front face of device 10. Substrates 146A and 146B may, for example,be sufficiently narrow so as to allow the N antennas distributed acrosssubstrate 146A and 146B to perform VSWR measurements through an inactivearea of a display on the front face of device (e.g., an area of thedisplay that is overlapped by a dielectric cover layer and that islaterally interposed between an active light-emitting area of thedisplay and peripheral conductive housing structures for device 10). Thefirst and second sets of antennas may form respective one-dimensionalphased antenna arrays 156 if desired. Additionally or alternatively, theN antennas may be disposed in a two-dimensional array pattern on one ormore substrates 146.

These examples are merely illustrative. Some or all of the N antennas 40need not be disposed on substrate 146 or arranged in any array pattern.More generally, the N antennas 40 used to measure the angular locationof external object 46 may be distributed across any desired locations ondevice 10. FIG. 12 is a top view showing illustrative locations fordistributing some or all of the N antennas 40 used to measure theangular location of external object 46.

As shown in FIG. 12 , one or more of the N antennas 40 may be locatedwithin one or more regions 164 on or within device 10 such as region164-1 at the top-left corner of device 10, region 164-2 at the top-rightcorner of device 10, region 164-3 at the bottom-left corner of deviceregion 164-4 at the bottom-right corner of device 10, one or moreregions 164-5 within a central region of device 10, and/or one or moreregions 164-6 laterally interposed between an active area of a displayfor device 10 and housing 12.

Separating two or more of the N antennas 40 by relatively largedistances and increasing the number N of antennas 40 used to performVSWR measurements may increase the resolution with which controlcircuitry 14 is able to determine the angular location of externalobject 46. Control circuitry 14 may determine the angular location ofexternal object 46 with an angular resolution of as fine as 1-2°, forexample. In the example of FIG. 12 , one or more of the N antennas 40located in regions 164-1, 164-2, 164-3, and 164-4 may have radiatingelements (e.g., antenna resonating element arms) formed from conductivesegments of housing 12 (e.g., peripheral conductive housing structuresthat run around the lateral periphery of device 10) that areseparated/defined by dielectric-filled gaps 162 in housing 12. Theantennas formed from conductive portions of housing 12 may also be usedto convey cellular telephone data, WLAN data, GPS data, etc. The exampleof FIG. 12 is merely illustrative. In general, housing 12 may have anydesired shape.

The methods and operations described above in connection with FIGS. 1-12may be performed by the components of device 10 using software,firmware, and/or hardware (e.g., dedicated circuitry or hardware).Software code for performing these operations may be stored onnon-transitory computer readable storage media (e.g., tangible computerreadable storage media) stored on one or more of the components ofdevice 10 (e.g., storage circuitry 16 of FIG. 1 ). The software code maysometimes be referred to as software, data, instructions, programinstructions, or code. The non-transitory computer readable storagemedia may include drives, non-volatile memory such as non-volatilerandom-access memory (NVRAM), removable flash drives or other removablemedia, other types of random-access memory, etc. Software stored on thenon-transitory computer readable storage media may be executed byprocessing circuitry on one or more of the components of device 10(e.g., processing circuitry 18 of FIG. 1 , etc.). The processingcircuitry may include microprocessors, central processing units (CPUs),application-specific integrated circuits with processing circuitry, orother processing circuitry. The components of FIGS. 1 and 2 may beimplemented using hardware (e.g., circuit components, digital logicgates, etc.) and/or using software where applicable.

Device 10 may gather and/or use personally identifiable information. Itis well understood that the use of personally identifiable informationshould follow privacy policies and practices that are generallyrecognized as meeting or exceeding industry or governmental requirementsfor maintaining the privacy of users. In particular, personallyidentifiable information data should be managed and handled so as tominimize risks of unintentional or unauthorized access or use, and thenature of authorized use should be clearly indicated to users.

The foregoing is merely illustrative and various modifications can bemade to the described embodiments. The foregoing embodiments may beimplemented individually or in any combination.

What is claimed is:
 1. An electronic device comprising: a first antennaconfigured to transmit a first radio-frequency signal; a first voltagestanding wave ratio (VSWR) sensor communicably coupled to the firstantenna and configured to perform a first VSWR measurement using thefirst radio-frequency signal; a second antenna configured to transmit asecond radio-frequency signal; a second VSWR sensor communicably coupledto the second antenna and configured to perform a second VSWRmeasurement using the second radio-frequency signal; and one or moreprocessors configured to detect a gesture based on the first VSWRmeasurement and the second VSWR measurement.
 2. The electronic device ofclaim 1, further comprising: a display, the one or more processors beingconfigured to coordinate, based on the detected gesture, an on-screenaction displayed by the display.
 3. The electronic device of claim 1,further comprising: a third antenna configured to transmit a thirdradio-frequency signal; and a third VSWR sensor communicably coupled tothe third antenna and configured to perform a third VSWR measurementusing the third radio-frequency signal, the one or more processors beingconfigured to detect the gesture based on the third VSWR measurement. 4.The electronic device of claim 1, further comprising: a substrate, thefirst antenna and the second antenna being disposed on the substrate. 5.The electronic device of claim 4, further comprising: a phased antennaarray configured to convey a beam of radio-frequency signals, the phasedantenna array including the first antenna and the second antenna.
 6. Theelectronic device of claim 5, the one or more processors beingconfigured to adjust a direction of the beam based on the detectedgesture.
 7. The electronic device of claim 4, further comprising: afirst substrate, the first antenna being disposed on the firstsubstrate; and a second substrate different from the first substrate,the second antenna being disposed on the second substrate.
 8. Theelectronic device of claim 7, further comprising: a first phased antennaarray configured to convey a first beam of radio-frequency signals, thefirst phased antenna array including the first antenna; and a secondphased antenna array configured to convey a second beam ofradio-frequency signals, the second phased antenna array including thesecond antenna.
 9. The electronic device of claim 1, the one or moreprocessors being configured to: detect a first range between theelectronic device and an external object based on the first VSWRmeasurement; detect a second range between the electronic device and theexternal object based on the second VSWR measurement; and detect thegesture based on the first range and the second range.
 10. Theelectronic device of claim 1, the one or more processors beingconfigured to detect the gesture based on a change in the first VSWRmeasurement over time and a change in the second VSWR measurement overtime.
 11. A method of operating an electronic device, the methodcomprising: transmitting, using a first antenna, a first radio-frequencysignal; transmitting, using a second antenna, a second radio-frequencysignal; generating, using a first voltage standing wave ratio (VSWR)sensor, a first scattering parameter value based on the firstradio-frequency signal; generating, using a second VSWR sensor, a secondscattering parameter value based on the second radio-frequency signal;and detecting, using one or more processors, a gesture based on thefirst scattering parameter value and the second first scatteringparameter value.
 12. The method of claim 11, further comprising:transmitting, using a third antenna, a third radio-frequency signal; andgenerating, using a third VSWR sensor, a third scattering parametervalue based on the third radio-frequency signal, wherein detecting thegesture comprises detecting the gesture based on the third firstscattering parameter value.
 13. The method of claim 11, furthercomprising: transmitting, using a fourth antenna, a fourthradio-frequency signal; and generating, using a fourth VSWR sensor, afourth scattering parameter value based on the fourth radio-frequencysignal, wherein detecting the gesture comprises detecting the gesturebased on the fourth first scattering parameter value.
 14. The method ofclaim 11, wherein transmitting the second radio-frequency signalcomprises transmitting the second radio-frequency signal concurrent withtransmission of the first radio-frequency signal by the first antenna.15. The method of claim 11, wherein the first scattering parameter valuecomprises a first reflection coefficient associated with the firstantenna and the second scattering parameter value comprises a secondreflection coefficient associated with the second antenna.
 16. Themethod of claim 11, further comprising: displaying images using adisplay; and adjusting, using the one or more processors, the imagesbased on the detected gesture.
 17. An electronic device comprising: aphased antenna array having a first antenna on a substrate and a secondantenna on the substrate, the first antenna being configured to transmita first radio-frequency signal, the second antenna being configured totransmit a second radio-frequency signal, and the phased antenna arraybeing configured to form a signal beam in a beam pointing direction; afirst voltage standing wave ratio (VSWR) sensor communicably coupled tothe first antenna and configured to perform a first VSWR measurementusing the first radio-frequency signal; a second VSWR sensorcommunicably coupled to the second antenna and configured to perform asecond VSWR measurement using the second radio-frequency signal; and oneor more processors configured to adjust, based on the first VSWRmeasurement and the second VSWR measurement, the beam pointing directionof the signal beam formed by the phased antenna array.
 18. Theelectronic device of claim 17, the one or more processors being furtherconfigured to: identify a location of an external object based on thefirst VSWR measurement and the second VSWR measurement; and adjust thebeam pointing direction to point away from the identified location ofthe external object.
 19. The electronic device of claim 17, wherein thephased antenna array has a third antenna on the substrate and configuredto transmit a third radio-frequency signal, the electronic devicefurther comprising: a third VSWR sensor communicably coupled to thethird antenna and configured to perform a third VSWR measurement usingthe third radio-frequency signal, the one or more processors beingconfigured to adjust the beam pointing direction based on the third VSWRmeasurement.
 20. The electronic device of claim 19, wherein the firstantenna and the second antenna are aligned along a first axis, thesecond antenna and the third antenna being aligned along a second axisorthogonal to the first axis.